The aim of the proposed research is to investigate a new psychophysical approach to the measurement and quantification of a centrally synthesized percept. The percept, in the present case an auditory illusion, results from the central synthesis of a pulsating stream of stimulation. The stream results in a perceptual unified whole, often referred to as "Auditory Streaming", "Continuity", or the "Pulsation Threshold". The illusion is a consequence of two factors: the stimulus parameters and the subject's personal experience and decisions. The latter factor has prevented investigators from obtaining a non-biased measure of the synthesized illusion. The goal is to investigate a psychophysical approach to the objective, unbiased, quantification of the illusion. The procedures entail the generation of auditory stimuli (both sinusoidal and complex) and their presentation to subjects seated in a sound attenuated chamber. The long term objectives, in addition to the important aspect of obtaining the first objective measure of the illusion, are to clarify the conditions underlying the perceptual phenomenon. Because the illusion has been shown to be a factor in the perception of speech and music, it is important for the long term understanding of human auditory perception.